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feat: rewrite
Signed-off-by: Henry Schreiner <[email protected]> feat: deduce C/CXX if possible Signed-off-by: Henry Schreiner <[email protected]> fix: better handling of output Signed-off-by: Henry Schreiner <[email protected]> docs: add info Signed-off-by: Henry Schreiner <[email protected]>
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‎README.md

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<!-- SPHINX-START -->
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This provides helpers for using Cython. Use:
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```cmake
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find_package(Cython MODULE REQUIRED VERSION 3.0)
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include(UseCython)
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```
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If you find Python beforehand, the search will take this into account. You can
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specify a version range on CMake 3.19+. This will define a `Cython::Cython`
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target (along with a matching `CYTHON_EXECUTABLE` variable). It will also
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provide the following helper function:
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```cmake
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cython_transpile(<pyx_file>
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[LANGUAGE C | CXX]
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[CYTHON_ARGS <args> ...]
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[OUTPUT <OutputFile>]
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[OUTPUT_VARIABLE <OutputVariable>]
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)
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```
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This function takes a pyx file and makes a matching `.c` / `.cxx` file in the
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current binary directory (exact path can be specified with `OUTPUT`). The
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location of the produced file is placed in the variable specified by
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`OUTPUT_VARIABLE` if given. Extra arguments to the Cython executable can be
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given with `CYTHON_ARGS`, and if this is not set, it will take a default from a
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`CYTHON_ARGS` variable.
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If the `LANGUAGE` is not given, and both `C` and `CXX` are enabled globally,
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then the language will try to be deduced from a `# distutils: language=...`
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comment in the source file, and C will be used if not found.
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This utility relies on the `DEPFILE` feature introduced for Ninja in CMake 3.7,
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and added for Make in CMake 3.20, and Visual Studio & Xcode in CMake 3.21.
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## Example
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```cmake
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find_package(
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Python
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COMPONENTS Interpreter Development.Module
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REQUIRED)
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find_package(Cython MODULE REQUIRED)
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cython_transpile(simple.pyx LANGUAGE C OUTPUT_VARIABLE simple_c)
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python_add_library(simple MODULE "${simple_c}" WITH_SOABI)
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```
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## scikit-build-core
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To use this package with scikit-build-core, you need to include it in your build
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requirements:
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```toml
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[build-system]
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requires = ["scikit-build-core", "cython", "cython-cmake"]
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build-backend = "scikit_build_core.build"
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```
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It is also recommended to require CMake 3.21:
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```toml
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[tool.scikit-build]
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cmake.version = ">=3.21"
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```
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## Vendoring
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You can vendor FindCython and/or UseCython into your package, as well. This

‎src/cython_cmake/cmake/UseCython.cmake

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# )
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#
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# Python_add_library(_hello
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# MODULE ${_hello_source_files}
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# MODULE "${_hello_source_file}"
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# WITH_SOABI
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# )
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#
@@ -79,16 +79,19 @@ if(CMAKE_VERSION VERSION_LESS "3.8")
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endif()
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function(Cython_transpile)
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set(_options )
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set(_one_value LANGUAGE OUTPUT OUTPUT_VARIABLE)
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set(_multi_value CYTHON_ARGS)
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cmake_parse_arguments(_args
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"${_options}"
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"${_one_value}"
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"${_multi_value}"
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${ARGN}
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cmake_parse_arguments(
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PARSE_ARGV 0
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CYTHON
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""
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"OUTPUT;LANGUAGE;OUTPUT_VARIABLE"
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"CYTHON_ARGS"
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)
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set(ALL_INPUT ${CYTHON_UNPARSED_ARGUMENTS})
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list(LENGTH ALL_INPUT INPUT_LENGTH)
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if(NOT INPUT_LENGTH EQUAL 1)
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message(FATAL_ERROR "One and only one input file must be specified, got '${ALL_INPUT}'")
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endif()
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list(GET ALL_INPUT 0 INPUT)
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if(DEFINED CYTHON_EXECUTABLE)
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set(_cython_command "${CYTHON_EXECUTABLE}")
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endif()
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# Default to CYTHON_ARGS if argument not specified
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if(NOT _args_CYTHON_ARGS AND DEFINED CYTHON_ARGS)
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set(_args_CYTHON_ARGS "${CYTHON_ARGS}")
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endif()
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# Get input
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set(_source_files ${_args_UNPARSED_ARGUMENTS})
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list(LENGTH _source_files input_length)
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if(NOT input_length EQUAL 1)
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message(FATAL_ERROR "One and only one input file must be specified, got '${_source_files}'")
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if(NOT CYTHON_CYTHON_ARGS AND DEFINED CYTHON_ARGS)
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set(CYTHON_CYTHON_ARGS "${CYTHON_ARGS}")
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endif()
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function(_transpile _source_file generated_file language)
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if(language STREQUAL "C")
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set(_language_arg "")
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elseif(language STREQUAL "CXX")
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set(_language_arg "--cplus")
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else()
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message(FATAL_ERROR "_transpile language must be one of C or CXX")
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endif()
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set_source_files_properties(${generated_file} PROPERTIES GENERATED TRUE)
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# Generated depfile is expected to have the ".dep" extension and be located along
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# side the generated source file.
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set(_depfile ${generated_file}.dep)
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set(_depfile_arg "-M")
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# Normalize the input path
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get_filename_component(_source_file "${_source_file}" ABSOLUTE)
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# Pretty-printed output names
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file(RELATIVE_PATH generated_file_relative
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${CMAKE_BINARY_DIR} ${generated_file})
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file(RELATIVE_PATH source_file_relative
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${CMAKE_SOURCE_DIR} ${_source_file})
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set(comment "Generating ${_language} source '${generated_file_relative}' from '${source_file_relative}'")
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# Get output directory to ensure its exists
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get_filename_component(output_directory "${generated_file}" DIRECTORY)
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get_source_file_property(pyx_location ${_source_file} LOCATION)
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# Add the command to run the compiler.
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add_custom_command(
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OUTPUT ${generated_file}
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COMMAND
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${CMAKE_COMMAND} -E make_directory ${output_directory}
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COMMAND
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${_cython_command}
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${_language_arg}
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"${_args_CYTHON_ARGS}"
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${_depfile_arg}
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${pyx_location}
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--output-file ${generated_file}
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COMMAND_EXPAND_LISTS
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MAIN_DEPENDENCY
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${_source_file}
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DEPFILE
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${_depfile}
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VERBATIM
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COMMENT ${comment}
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)
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endfunction()
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function(_set_output _input_file _language _output_var)
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if(_language STREQUAL "C")
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set(_language_extension "c")
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elseif(_language STREQUAL "CXX")
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set(_language_extension "cxx")
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else()
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message(FATAL_ERROR "_set_output language must be one of C or CXX")
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endif()
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# Can use cmake_path for CMake 3.20+
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# cmake_path(GET _input_file STEM basename)
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get_filename_component(_basename "${_input_file}" NAME_WE)
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if(IS_ABSOLUTE ${_input_file})
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file(RELATIVE_PATH _input_relative ${CMAKE_CURRENT_SOURCE_DIR} ${_input_file})
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else()
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set(_input_relative ${_input_file})
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endif()
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get_filename_component(_output_relative_dir "${_input_relative}" DIRECTORY)
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string(REPLACE "." "_" _output_relative_dir "${_output_relative_dir}")
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if(_output_relative_dir)
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set(_output_relative_dir "${_output_relative_dir}/")
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endif()
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set(${_output_var} "${CMAKE_CURRENT_BINARY_DIR}/${_output_relative_dir}${_basename}.${_language_extension}" PARENT_SCOPE)
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endfunction()
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set(generated_files)
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list(GET _source_files 0 _source_file)
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# Set target language
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set(_language ${_args_LANGUAGE})
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if(NOT _language)
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if(NOT CYTHON_LANGUAGE)
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get_property(_languages GLOBAL PROPERTY ENABLED_LANGUAGES)
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if("C" IN_LIST _languages AND "CXX" IN_LIST _languages)
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# Try to compute language. Returns falsy if not found.
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_cython_compute_language(_language ${_source_file})
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_cython_compute_language(CYTHON_LANGUAGE ${INPUT})
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message(STATUS "${CYTHON_LANGUAGE}")
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elseif("C" IN_LIST _languages)
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# If only C is enabled globally, assume C
210-
set(_language "C")
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set(CYTHON_LANGUAGE C)
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elseif("CXX" IN_LIST _languages)
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# Likewise for CXX
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set(_language "CXX")
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set(CYTHON_LANGUAGE CXX)
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else()
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message(FATAL_ERROR "LANGUAGE keyword required if neither C nor CXX enabled globally")
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endif()
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endif()
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219-
if(NOT _language MATCHES "^(C|CXX)$")
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message(FATAL_ERROR "Cython_transpile LANGUAGE must be one of C or CXX")
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# Default to C if not found
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if(NOT CYTHON_LANGUAGE)
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set(CYTHON_LANGUAGE C)
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endif()
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if(CYTHON_LANGUAGE STREQUAL C)
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set(language_arg "")
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set(language_ext ".c")
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elseif(CYTHON_LANGUAGE STREQUAL CXX)
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set(language_arg "--cplus")
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set(language_ext ".cxx")
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else()
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message(FATAL_ERROR "cython_compile_pyx LANGUAGE must be one of C or CXX")
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endif()
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# Place the cython files in the current binary dir if no path given
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if(NOT _args_OUTPUT)
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_set_output(${_source_file} ${_language} _args_OUTPUT)
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elseif(NOT IS_ABSOLUTE ${_args_OUTPUT})
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set(_args_OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/${_args_OUTPUT}")
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# Can use cmake_path for CMake 3.20+
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if(NOT CYTHON_OUTPUT)
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get_filename_component(basename "${INPUT}" NAME_WE)
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set(CYTHON_OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/${basename}${language_ext}")
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elseif(NOT IS_ABSOLUTE CYTHON_OUTPUT)
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set(CYTHON_OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/${CYTHON_OUTPUT}")
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endif()
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230-
set(generated_file ${_args_OUTPUT})
231-
_transpile(${_source_file} ${generated_file} ${_language})
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list(APPEND generated_files ${generated_file})
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# Normalize the input path
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get_filename_component(INPUT "${INPUT}" ABSOLUTE)
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set_source_files_properties("${INPUT}" PROPERTIES GENERATED TRUE)
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# Output variable only if set
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if(_args_OUTPUT_VARIABLE)
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set(_output_variable ${_args_OUTPUT_VARIABLE})
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set(${_output_variable} ${generated_files} PARENT_SCOPE)
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if(CYTHON_OUTPUT_VARIABLE)
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set(${CYTHON_OUTPUT_VARIABLE} "${CYTHON_OUTPUT}" PARENT_SCOPE)
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endif()
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# Generated depfile is expected to have the ".dep" extension and be located
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# along side the generated source file.
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set(depfile_path "${CYTHON_OUTPUT}.dep")
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# Pretty-printed output name
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file(RELATIVE_PATH generated_file_relative "${CMAKE_BINARY_DIR}" "${CYTHON_OUTPUT}")
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file(RELATIVE_PATH input_file_relative "${CMAKE_SOURCE_DIR}" "${INPUT}")
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172+
# Add the command to run the compiler.
173+
add_custom_command(
174+
OUTPUT
175+
"${CYTHON_OUTPUT}"
176+
"${depfile_path}"
177+
COMMAND
178+
${_cython_command}
179+
${language_arg}
180+
${CYTHON_CYTHON_ARGS}
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--depfile
182+
"${INPUT}"
183+
--output-file "${CYTHON_OUTPUT}"
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MAIN_DEPENDENCY
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"${INPUT}"
186+
DEPFILE
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"${depfile_path}"
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VERBATIM
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COMMENT
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"Cythonizing source ${input_file_relative} to output ${generated_file_relative}"
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)
192+
193+
endfunction()
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function(_cython_compute_language OUTPUT_VARIABLE FILENAME)
196+
file(READ "${FILENAME}" FILE_CONTENT)
197+
set(REGEX_PATTERN [=[^[[:space:]]*#[[:space:]]*distutils:.*language[[:space:]]*=[[:space:]]*(c\\+\\+|c)]=])
198+
string(REGEX MATCH "${REGEX_PATTERN}" MATCH_RESULT "${FILE_CONTENT}")
199+
string(TOUPPER "${MATCH_RESULT}" LANGUAGE_NAME)
200+
string(REPLACE "+" "X" LANGUAGE_NAME "${LANGUAGE_NAME}")
201+
set(${OUTPUT_VARIABLE} ${LANGUAGE_NAME} PARENT_SCOPE)
240202
endfunction()
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function(_cython_compute_language OUTPUT_VARIABLE FILENAME)

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